Update

Snow and Ice Accretion

The study and assessment of snow and ice accretion — the process by which snow and ice build up on solid objects exposed to freezing precipitation — will be the purpose of a new ASTM task group within Subcommittee E06.55 on Performance of Building Enclosures, part of ASTM International Committee E06 on Performance of Buildings.

“There is a growing need to better understand the impacts and the influence of decisions in envelope design, especially when improved energy performance is the goal,” says Roman Stangl, director – ice and snow specialist, Northern Microclimate Inc. Stangl and Mike Carter, president, Northern Microclimate Inc., are co-chairs of the new task group.

“The key issue can be explained as simply that less energy creates colder building skins, which allow greater snow and ice accretion during winter storm events,” says Stangl. “This snow or ice then slides, falls or is windblown onto urban sidewalks, streets or neighboring buildings, creating a hazard for people and property.”

Stangl says that the first topic the new task group plans to address is procedures for facade testing in an environmental test chamber. This testing will provide a format for quality information gathering and help to build the knowledge base for various facades.

“The hope is that standardized testing will lead to the development of a database of knowledge on the many variations of facades, which in turn will allow for the future creation of criteria and standards for the design industry to use for construction in climates with winter precipitation,” says Stangl. “Similar test procedures already exist for issues like water penetration and wind pressure, however, not for the variables that present themselves during winter months.”

Stangl notes that the life cycle of winter precipitation on a facade can create a challenge for testing. Snow on a facade can age and harden, transform into slippery ice sheets, become heavy slush or slowly melt and refreeze.

According to Stangl, standards developed by the task group will be used by engineers, consultants and test laboratories, guiding them through established and proven methods to produce consistent results when testing building facades or facade components for snow and ice accretion.

The E06.55.13 task group will have its first meeting during the ASTM October committee week in Jacksonville, Fla. All interested parties are welcome to participate in the task group’s standards developing activities. Stangl says that the task group would like to see participation from test laboratories; researchers; snow retention manufacturers/suppliers; facade consultants, designers and manufacturers; and architects.